diff --git a/.Rbuildignore b/.Rbuildignore
index 28829a6..a7f5b35 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -9,3 +9,4 @@
 ^\.env$
 ^doc$
 ^Meta$
+^scripts$
diff --git a/DESCRIPTION b/DESCRIPTION
index 6849728..babf18e 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: ohcleandat
 Type: Package
 Title: One Health Data Cleaning and Quality Checking Package
-Version: 0.3.11
+Version: 0.3.12
 Authors@R: c(
     person("Collin", "Schwantes", email = "schwantes@ecohealthalliance.org", role = c("cre", "aut"), comment = c(ORCID = "0000-0003-4014-4896")),
     person("Johana", "Teigen", email = "teigen@ecohealthalliance.org", role = "aut", comment = c(ORCID = "0000-0002-6209-2321")),
diff --git a/NEWS.md b/NEWS.md
index 5dcb9ef..ab8e724 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,8 @@
+# ohcleandat 0.3.12
+
+* `expand_frictionless_metadata` can add and remove fields from the metadata depending
+on the structural metadata supplied. 
+
 # ohcleandat 0.3.11
 
 * obfuscate gps can now handle NAs
diff --git a/R/create_structural_metadata.R b/R/create_structural_metadata.R
index a207b41..546ad92 100644
--- a/R/create_structural_metadata.R
+++ b/R/create_structural_metadata.R
@@ -15,13 +15,13 @@
 #'
 #' The metadata table produced has the following elements
 #'
-#' `name` = The name of the field. This is taken as is from `data`.
-#' `description` = Description of that field. May be provided by controlled vocabulary
-#' `units` = Units of measure for that field. May or may not apply
-#' `term_uri` = Universal Resource Identifier for a term from a controlled vocabulary or schema
-#' `comments` = Free text providing additional details about the field
-#' `primary_key` = `TRUE` or `FALSE`, Uniquely identifies each record in the data
-#' `foreign_key` = `TRUE` or `FALSE`, Allows for linkages between data sets. Uniquely identifies
+#' - `name` = The name of the field. This is taken as is from `data`.
+#' - `description` = Description of that field. May be provided by controlled vocabulary
+#' - `units` = Units of measure for that field. May or may not apply
+#' - `term_uri` = Universal Resource Identifier for a term from a controlled vocabulary or schema
+#' - `comments` = Free text providing additional details about the field
+#' - `primary_key` = `TRUE` or `FALSE`, Uniquely identifies each record in the data
+#' - `foreign_key` = `TRUE` or `FALSE`, Allows for linkages between data sets. Uniquely identifies
 #'  records in a different data set
 #'
 #'
diff --git a/R/modify_frictionless_metadata.R b/R/modify_frictionless_metadata.R
index 7d54c20..d487861 100644
--- a/R/modify_frictionless_metadata.R
+++ b/R/modify_frictionless_metadata.R
@@ -1,7 +1,9 @@
 #' Expand Frictionless Metadata with structural metadata
 #'
-#' Loops over elements in the structural metadata and adds them to frictionless
-#' metadata schema. Will overwrite existing values.
+#' Loops over elements in the structural metadata and adds
+#' them to the frictionless metadata schema. Will overwrite existing values and
+#' remove any fields from the datapackage metadata not listed in the structural
+#' metadata.
 #'
 #' @param structural_metadata Dataframe. Structural metadata from
 #' `create_structural_metadata` or `update_structural_metadata`
@@ -27,7 +29,7 @@
 #' # update structural metadata
 #' write.csv(data_codebook,"my/codebook.csv", row.names = FALSE)
 #'
-#' data_codebook_updated <- read.csv(""my/codebook.csv"")
+#' data_codebook_updated <- read.csv("my/codebook.csv")
 #'
 #' # create frictionless package - this is done automatically with the
 #' # deposits package
@@ -61,9 +63,29 @@ expand_frictionless_metadata <- function(structural_metadata,
 
   ## build up schema based on structural metadata
 
-  for(idx in 1:length(my_data_schema$fields)){
+  ## drop fields that were removed from the structural metadata
+  if(nrow(structural_metadata) <= length(my_data_schema$fields)){
+    my_data_schema$fields <- my_data_schema$fields[1:nrow(structural_metadata)]
+  }
+
+  # for each row, update the schema
+  for(idx in 1:nrow(structural_metadata)){
     # item to build out
-    x <- my_data_schema$fields[[idx]]
+    ## row may not exist in the original data.
+     x <- tryCatch(
+      expr = {
+        ## get the fields item we want to update
+        my_data_schema$fields[[idx]]
+      },
+      error = function(e){
+        ## use the first index item
+        msg<- sprintf("Adding %s to frictionless metadata",structural_metadata$name[[idx]])
+        message(msg)
+        my_data_schema$fields[[1]]
+      }
+    )
+
+
     for(idy in 1:length(structural_metadata)){
 
       y <- structural_metadata[idx,idy][[1]]
@@ -85,6 +107,8 @@ expand_frictionless_metadata <- function(structural_metadata,
     my_data_schema$fields[[idx]] <- x
   }
 
+
+  ## prune the properties of items in the schema, does not remove fields
   if(prune_datapackage){
     my_data_schema <- prune_datapackage(my_data_schema,structural_metadata)
   }
@@ -104,7 +128,7 @@ expand_frictionless_metadata <- function(structural_metadata,
 }
 
 
-#' Prune data pacakge
+#' Prune field properties in a data package
 #'
 #' method to remove properties from the metadata for a dataset in a datapackage
 #'
@@ -136,3 +160,5 @@ prune_datapackage <- function(my_data_schema, structural_metadata){
 
   return(my_data_schema_pruned)
 }
+
+
diff --git a/man/create_structural_metadata.Rd b/man/create_structural_metadata.Rd
index 9445cc4..d6d3ceb 100644
--- a/man/create_structural_metadata.Rd
+++ b/man/create_structural_metadata.Rd
@@ -31,16 +31,17 @@ generated then joined to pre-existing metadata via field names.
 }
 \details{
 The metadata table produced has the following elements
-
-\code{name} = The name of the field. This is taken as is from \code{data}.
-\code{description} = Description of that field. May be provided by controlled vocabulary
-\code{units} = Units of measure for that field. May or may not apply
-\code{term_uri} = Universal Resource Identifier for a term from a controlled vocabulary or schema
-\code{comments} = Free text providing additional details about the field
-\code{primary_key} = \code{TRUE} or \code{FALSE}, Uniquely identifies each record in the data
-\code{foreign_key} = \code{TRUE} or \code{FALSE}, Allows for linkages between data sets. Uniquely identifies
+\itemize{
+\item \code{name} = The name of the field. This is taken as is from \code{data}.
+\item \code{description} = Description of that field. May be provided by controlled vocabulary
+\item \code{units} = Units of measure for that field. May or may not apply
+\item \code{term_uri} = Universal Resource Identifier for a term from a controlled vocabulary or schema
+\item \code{comments} = Free text providing additional details about the field
+\item \code{primary_key} = \code{TRUE} or \code{FALSE}, Uniquely identifies each record in the data
+\item \code{foreign_key} = \code{TRUE} or \code{FALSE}, Allows for linkages between data sets. Uniquely identifies
 records in a different data set
 }
+}
 \examples{
 \dontrun{
 df <- data.frame(a = 1:10, b = letters[1:10])
diff --git a/man/expand_frictionless_metadata.Rd b/man/expand_frictionless_metadata.Rd
index c207064..5adf538 100644
--- a/man/expand_frictionless_metadata.Rd
+++ b/man/expand_frictionless_metadata.Rd
@@ -29,8 +29,10 @@ be removed?}
 Updates the datapackage, returns nothing
 }
 \description{
-Loops over elements in the structural metadata and adds them to frictionless
-metadata schema. Will overwrite existing values.
+Loops over elements in the structural metadata and adds
+them to the frictionless metadata schema. Will overwrite existing values and
+remove any fields from the datapackage metadata not listed in the structural
+metadata.
 }
 \examples{
 \dontrun{
@@ -45,7 +47,7 @@ data_codebook  <- create_structural_metadata(data)
 # update structural metadata
 write.csv(data_codebook,"my/codebook.csv", row.names = FALSE)
 
-data_codebook_updated <- read.csv(""my/codebook.csv"")
+data_codebook_updated <- read.csv("my/codebook.csv")
 
 # create frictionless package - this is done automatically with the
 # deposits package
diff --git a/man/prune_datapackage.Rd b/man/prune_datapackage.Rd
index 17dab6e..acd14d8 100644
--- a/man/prune_datapackage.Rd
+++ b/man/prune_datapackage.Rd
@@ -2,7 +2,7 @@
 % Please edit documentation in R/modify_frictionless_metadata.R
 \name{prune_datapackage}
 \alias{prune_datapackage}
-\title{Prune data pacakge}
+\title{Prune field properties in a data package}
 \usage{
 prune_datapackage(my_data_schema, structural_metadata)
 }
diff --git a/scripts/debug_expand_df.R b/scripts/debug_expand_df.R
new file mode 100644
index 0000000..a6e63df
--- /dev/null
+++ b/scripts/debug_expand_df.R
@@ -0,0 +1,46 @@
+devtools::load_all()
+
+
+# read in data
+
+
+
+df <- read.csv("vignettes/data_examples/my_data.csv")
+
+# create codebook
+
+structural_metadata <- create_structural_metadata(df,primary_key = "key",
+                                       foreign_key = c("measured_by","site_name"))
+
+# create data package
+
+
+dp <- frictionless::create_package() |>
+      frictionless::add_resource(resource_name = "my_data",
+                                 data = df)
+
+frictionless::write_package(package = dp,
+                            directory = "vignettes/data_examples")
+
+expand_frictionless_metadata(structural_metadata = structural_metadata,
+                             resource_name = "my_data",
+                             resource_path = "vignettes/data_examples/my_data.csv",
+                             data_package_path = "vignettes/data_examples/datapackage.json"
+                            )
+
+## drop a measured_by column
+
+df <- read.csv("vignettes/data_examples/my_data.csv")
+
+# create codebook
+
+structural_metadata_2 <- create_structural_metadata(df,
+                                                  primary_key = "key",
+                                                  foreign_key = c("site_name"))
+
+
+expand_frictionless_metadata(structural_metadata = structural_metadata_2,
+                             resource_name = "my_data",
+                             resource_path = "vignettes/data_examples/my_data.csv",
+                             data_package_path = "vignettes/data_examples/datapackage.json"
+)
diff --git a/vignettes/data_examples/my_data.csv b/vignettes/data_examples/my_data.csv
index 8846be9..b849f8c 100644
--- a/vignettes/data_examples/my_data.csv
+++ b/vignettes/data_examples/my_data.csv
@@ -1,11 +1,11 @@
-"date","measurement","measured_by","site_name","key"
-2024-08-26,43,"Johana","c",1
-2024-08-27,9,"Johana","c",2
-2024-08-28,79,"Johana","c",3
-2024-08-29,17,"Collin","a",4
-2024-08-30,61,"Johana","e",5
-2024-08-31,30,"Collin","b",6
-2024-09-01,58,"Collin","a",7
-2024-09-02,27,"Johana","d",8
-2024-09-03,52,"Johana","d",9
-2024-09-04,82,"Collin","e",10
+date,measurement,measured_by,site_name,key
+2024-08-26,43,Johana,c,1
+2024-08-27,9,Johana,c,2
+2024-08-28,79,Johana,c,3
+2024-08-29,17,Collin,a,4
+2024-08-30,61,Johana,e,5
+2024-08-31,30,Collin,b,6
+2024-09-01,58,Collin,a,7
+2024-09-02,27,Johana,d,8
+2024-09-03,52,Johana,d,9
+2024-09-04,82,Collin,e,10